Fire-alarm system.



No.876,512. 'PATENTEDJAN.14,1908.

M. A. ABRAHAMSON. I FIRE ALARM SYSTEM.

APPLICATION FILED IEB.1.1905. I y

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6 4 WMma/ZMWM No. 876,512. PATBNTED JAN. 14, 1908.- M. A. ABRAHAMSON.

FIRE ALARM SYSTEM.

APPLICATION FILED PEB.1,19,05.

5 SHEETS-SHEET 2.

No. 876,512. PATENTED JAN. 14, 1908.

M. A. ABRAHAMSON.

FIRE ALARM SYSTEM.

APPLIQATION FILED IEB.1. 1905.

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MARTIN ARNOLD ABRAIIAMSON, OF COPENHAGEN, DENMARK.

FIRE-ALARM SYSTEM.

Specification of Letters Patent.

Patented Jan. 14, 1908.

Application filed February 1. 1905. Serial No. 243642.

T 0 all whom it may concern:

Be it known that I, MARTIN ARNOLD ABRAIIAMSON, civil engineer, subjectof Great Britain, residing at Copenhagen, in the Kingdom of Denmark,have invented new and useful Improvements in Fire- Alarm Systems, ofwhich the following is a specification.

My invention has for its object the construction of a fire alarm systemfor buildings, and more especially relates to that class of systemsknown as automatic fire alarms, and the principal objects of theinvention are1. To automatically register in a build ing distinctivetrouble signals when any part of the system in the building is groundedor otherwise impaired so as to prevent the transmission of a firesignal. 2. To automatically register when the voltage of the source ofenergy has fallen so much as to require renewal. 3. To obtain animmediate or continuous alarm in such cases. l. To automaticallyregister a distinctive danger call in cases of excessive heating or anabnormal rate of increase of temperature in any part of the buildingwhere the thermostats are located. 5. To automatically register at oneor more central stations when the conditions under 4 are increased.

Referring to the drawings in which like parts are similarlydesignatedFigure 1. is a diagrammatic representation of an open circuitsystem illustrating my invention. Fig. 2 is a' similar View of a closedcircuit system. Figs. 3 to 5 are similar views of modificationsillustrating the thermostats arranged in groups.

The thermostats a, Fig. 1, are of a well known type and carry a circuitclosing plug or contact 6.

The battery I) composed of any suitable cells or an accumulator battery,(the latter is preferred, on account of its constancy of potential,) isconnected by wire 1 whose parallel branches 10, 50 and 51 are united. toWire 52, relay magnet or magnets d back In the branches 50 and 51., ofwhich there may be any desired number, are placed the thermostats a inparallel groups I and II which are preferably placed a group for eachfloor of the building. The several thermostats a of each group areconnected in parallel to their respective branches 50, 51, in opencircuit in such a manner that current reduced in voltage may be sentthrough the line to indicate trouble,

or if followed by full potential current to send a fire alarm, and tothis end I have shown the thermostats a wired for both kinds of signalsin group I, and for trouble signals only in group II.

At the thermostat a are two pairs of contacts, 53, and 54, 56, the one,53, connected through resistance f and the one 54 connected through wireg to the point 3 in the main wire 1 and in parallel. The contacts 55 and56 are connected in series to point 4 in return wire 51. The thermostata carries the circuit closer e capable of bridging the spaces f and gbetween the two pairs of contacts, so that when the space f is bridgedcontacts 53 and 55 are connected and current reduced in voltage by theresistancef is closed through the circuit, and when the other twocontacts are bridged full strength current is closed through line. Eachgroup, I and II contains a magnetically released indicator 0 to indicatein which group I or II the trouble or fire is located. In group II Ihave shown the thermostats a wired only for trouble indications, and ifthe trouble should be found to be a fire, the fire alarm is manuallysent in by closing the circuit at 1' in the shunt circuit branch 10. Therelay magnet d which is the equivalent of the magnets operates twoarmatures i and j, one at each end, the one being weighted at 57 andelectrically connected by wire 5 to the one i. The armature 'i istherefore attracted by reason of low potential current and both areattracted by the high potential current in magnet d.

Low potential current will act to operate armature 'i to close a localbranch circuit as follows: battery 6 wire 2, magnet h, wire 58 armaturej, wire 5, armature i contact i wire 6 back to battery. Magnet h will beenergized to actuate its armature it that carries the insulated circuitcloser m to connect n and 0, thereby short circuiting the former paththrough the two armatures i and j and holding the apparatus in readinessto receive the fire signal by the higher potential current, the wires 2and 7 being connected by the armature h to close one of the two normallyopen points in the alarm circuit. Should the stronger potential currentnow be sent through the main circuit 51 or short circuit branch 10,armature will be attracted, closing a parallel local branch circuit asfollows: battery 5, wire 2, magnet 7c wire 59 contact y' armature j,wire 5, armature 6, contact i wire 6 back to battery; this will energizemagnet 7c to attract its armature' is to complete the following parallelalarm circuit battery 7), wire 2, contact 1), armature h wire 7 armature7c wire 8, signal bell q wire 9 back to battery. Should the highpotential current be sent in the first instance by accidentally closing1" or by forming a short circuit, electro magnet 7r alone becomesoperative, and circuit will not be closed at p, magnet It being cut outby opening its branch circuit at j The armatures 7t and 7c arepreferably provided with indicators, either of which acting singlyindicates trouble, but when acting together indicate fire and show thatthe firesignal circuit is closed. The breakage of the manual contact 1or of an indicator 0 will have no effect on the alarm circuit.

In Fig. 2 I have shown a closed circuit systern, there being shown byway of example four groups of thermostats, one group for each floor of abuilding, the groups being included in parallel between the batterywires 1 and 15, so that a description of the operation and arrangementof one of the groups will be suflicient.

Consideration of space on the drawing has made it possible to show onlymagnets of groups III and IV, the magnet for the other groups areidentical in operation and connection.

The thermostats are of a well-known con struction, comprising U-tubes ofglass closed at both ends with sealed-in platinum wires and filled witha volatile liquid and mercury, the latter under normal conditionsmaintaining all contacts closed, those in groups I and III producingboth trouble and fire signals, similar to group I, Fig. 1, and groups IIand IV are arranged to produce trouble signals only, the fire signalbeing sent in by breaking circuit at the manually operated circuitbreaker r.

The thermostats a in group I, Fig. 2, contain the mercury 9 having avolatile liquid. f above it the mercury being connected from one leg ofthe tube to the main wire 1 at 3, and the other leg closes circuitthrough two wires connected at 4 to branch 1 1 or the other thermostatsin series in said branch, as circumstances may require or demand, one ofsaid wires f designed. to transmit full potential current and the othercontaining a resi-stance 9 so that when the mercury is depressed belowwiref by the volatilized liquid the potential in the branch line 11 islowered, and when the mercury is depressed below 9 the circuit isentirely broken. In group III there are two similar thermostats a and aconnected in pairs and in series; when the mercury in a breaks contactit causes the current to pass through the resistance g and send atrouble signal, and when the one as in each pair breaks its contact 9the current is broken and a fire signal is sent in. In groups II and IV.the thermostats can, as already stated, only send a trouble signal asthey can only diminish the current by means of resistance g while theycannot break the circuit totally. If the trouble should. be found to befire, the fire alarm is manually sent in by breaking the circuit at 1'in wire 1. Each parallel branch circuit 11, 12, 13, 14 is connected to apair of relay magnets cl and d in series, which in turn are connected tothe return battery wire 15 common to all of them.

Then current of reduced potential passes through the two magnets byreason of a thermostat automatically causing the current through itsbranch to pass through a resistance g, armature i will be released fromrelay magnet d the screw preventing close contact between armature andmagnet core thereby rendering it sensitive to current reduction, andcloses a local battery circuit through contact i as follows: localbattery 1) wires 6 and 16, contact i, armature i,'wire 5, armaturecontact j wires 17 and 18, magnet h wire 60 back to battery I). Themagnet h is energized, attracts its armature it giving a trouble signalon the bell and moving the circuit closer m to bridge the contacts 8 atone of the open points on the fire alarm circuit wires 8 and 21preparatory to sending in the fire alarm when other open point isbridged. The circuit closer m when moved over by h to bridge thecontacts 8 stays in its operative position and cannot return to itsoriginal position even when 72 goes back to original position. Nowshould the circuit in any of wires 11., 12, .13, 1 1 or 1 be broken,either automatically by one of the thermostats or manually at r,armaturej is also released closing circuit at j to close the followinglocal branch circuit: battery If, wires 6 and 16, armature "L, wire 5armature j contact wires 19 and 20 and magnet back to battery Z). Magnet7c is also energized attracting its armature k to ring the bell thereforand move circuit closer m to close contacts 8 and complete the circuitof the fire alarm 8 and 9, by bridging wires 21 and 9 at the other openpoint. The circuit closer m is locked similarly as de scribed for m..Thus it will be seen that both it and It must be actuated to send a firealarm, 'L. a, first the trouble call must be sent in to operate armature7i and then the main branch circuit broken to actuate 7c. Should anythermostat circuits be accidentally broken, only armature 7c will beoperated, the magnet h being cut out of circuit by the intermediateaction of armature breaking the circuit of magnet h at j.

The auxiliary thermostats a (being maxi mum temperature thermostats) ingroups III'and IV are of importance, where the tem perature rises soslowly that the differential temperature thermostat a might possibly notact at all. They consist of U-shaped tubes open at one end. In theclosed leg there is a small quantity of a volatile liquid. over themercury, that will evaporate as soon as the temperature has risen to acertain point, whereby the mercury is depressed and the circuit throughthe platinum contacts is broken.

Fig. 3, is similar to Fig. 2 excepting that the thermostats are placedin their branch circuits in pairs of parallel circuits between thepoints 3 and 4 where one set, as groups I and III Fig. 3, correspond tothe path of current f in which there is substantially no resistance andare more sentitive than their companion thermostats in groups II and IV,which latter correspond to the parallel circuit through g in Fig. 2, theupper set serving to send in the trouble call and the combined action ofthe two sets being necessary to send in the lire alarm. In otherrespects the two figures are identical.

In Fig. 4 I have shown a modification where the thermostats areconnected in pairs of groups in parallel, I, II and III, IV, and eachpair of groups is provided with the necessary pair of relay magnets (1so that they form a unit. Each unit has its relay magnet d in closedseries with the magnets (Z by wires 22 and 23. Now it circuit is brokenat group I the lowermost relay magnet (Z becomes currentless, itsarmature i will drop closing contact at i to close the local circuit asfollows: local battery 7), magnet 7t wire 18, contact j, wire 5 armaturecontact i armature 1', wire 6 back to battery 7), thereby energizingmagnet 7b to bridge the contacts 5 between wires 8 and 2] preparatory tosending in the alarm signal. Since the upper relay magnet (Z is stillreceiving current through group II and wire 12 current through (Z is notcut otl, but as soon as current through group II is also broken thesecond armature i will drop, closing contact at j and closing thecircuit through magnet 71? as follows: local battery 7), wire 61, magnetZr, wire 20, contact 9' armature j, wire 5, through the pair ofarmatures i, their contacts i, wire 6 back to battery b, thus energizingA: to attract its armature 7: to operate to close circuit between 9 and21 and send in the fire alarm. If current be suddenly broken as at 7'before the operation of the thermostats, magnet 1c only will beenergized as stated in connection with Fig. 2.

In Fig. 5 I have shown a case where more than two groups of thermostatsare combined in parallel to form a unit, each group having its relaymagnet (Z. In this figure I have shown four groups in parallel similarto F 4, there being but one magnet (Z for all four of the groups. Incase circuit through one of the groups is broken only magnet 7b can beenergizedthen upon the subsequent breaking of the circuit through one ormore of the other groups, depending upon the strength of currentrequired to keep armature j in normal position-the ma net 7c will alsobe energized to send in the :ire alarm. In other respects the operationis like that in the figures just described for the closed circuitsystem, and further detailed description is deemed unnecessary.

I claim- 1. In a fire alarm system, a primary circuit, thermostatstherein controlling the current through the system, electro-magnetsenergized by current in said circuit, armatures controlled by saidmagnets under different current conditions regulated. by thethermostats, two auxiliary circuits controlled by said armatures, and athird circuit controlled by said two secondary circuits.

In a fire alarm system, a main circuit, thermostats therein controllingthe current through the system, electro-magi'iets energized by currentthrough the system, armatures controlled by said magnets under differentconditions which are dependent upon the thermostats, two auxiliarycircuits closed under different operative current conditions by saidarmatures, electro-magnets one in each of two said auxiliary circuits,armatures controlled by last mentioned electromagnets, and a thirdcircuit controlled by last mentioned armatures under one operativecurrent condition to send a fire alarm.

3. In a fire alarm system, a main circuit, thermostats therein, aresistance in shunt with the circuit and included in the circuit by saidthermostats, a pair of electro-magnets in the circuit, armatures forsaid magnets one of which is operated by current when directed throughthe resistance by said thermostats and the other armature operated underother current conditions controlled by the thermostats, an auxiliarycircuit closed by the first mentioned armature to give a danger signal,a second auxiliary circuit closed by both armatures to give a troublesignal, and a third circuit closed by the two secondary circuits beingclosed in succession.

4. In a fire alarm system, a main circuit, thermostats therein tocontrol three current conditions, no current, full current and anintermediate current condition, a pair of magnets and their armatures, asecond circuit, a magnet therein and its armature operated by theintermediate current condition on one of the magnets in the main circuitto give a trouble signal, a fire alarm circuit open at two points, oneof said points closed by the said magnet armature in the secondarycircuit, a third circuit closed by the second magnet in the main circuitto give a fire signal and simultaneously close the second open point inthe fire alarm circuit.

5. In a fire alarm system, the combination with a circuit containingthermostats, of relay magnets contained in said circuit, armaturestherefor of different sensitiveness, a

local circuit having two branches, a magnet in each branch, an armaturefor each magnet, an alarm circuit open at two points, the relay armatureof lesser sensitiveness adapted to close one of the branch circuits tooperate the armature of the magnet therein to close one of the points toindicate a trouble call and the relay armature of greater sensitivenessto close the other branch circuit to operate the armature of the magnettherein to complete the alarm circuit, substantially as described.

6. In a fire alarm system, the combination with a normally closedcircuit containing thermostats; of relay magnets therein their armaturesoperating under different current conditions, a local circuit having twobranches, a magnet and its armature in each branch, an alarm circuitopen at two points, the armature of one of the relay magnets closing oneof the branches when current through. the relay is reduced in voltage tocause the armature of the magnet in such branch. to close one of thepoints in the alarm circuit, and the armature of another relay magnetclosing the circuit in the other branch when current is -further reducedto cause the armature oi the magnet in such branch to complete thealarm. circuit, substantially as described.

7. In a fire alarm system, the combination with a normally closedcircuit containing thermostats and resistances automatically thrown incircuit by some of the thermostats; of a pair of relay magnets operatingunder difi erent current conditions, and a manually operated circuitbreaker in said circuit, a local circuit having two branches eachcontaining a magnet and its armature, an alarm circuit having twonormally open points each controlled "by an armature of a magnet in abranch, one of the relay magnets operated when current is reduced toclose one of the branch circuits and thereby close one of the openpoints, and upon subsequent reduction. of the current or breakage ofcircuit the armature of the other relay magnet closes the second branchcircuit to cause the armature of the magnet therein to complete thealarm circuit.

8. In a fire alarm system, a main circuit, a thermostat thereincontrolling the current through the system, two electromagnetic allyoperated circuit closing devices operated by dil'l'erent currentconditions in the main circuit, two auxiliary circuits controlled bysaid devices and a third circuit controlled by the electro-magneticcircuit closing devices in the main circuit. I

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

MARTIN ARNOLD ABRAIIAMSON.

WVitnesses L. HOFMAN LACEY, ALBERT G. MIOHELSON.

